errors: make properties mutable

Userland code can break if it depends on a mutable `code` property for
errors. Allow users to change the `code` property but do not propagate
changes to the error `name`.

Additionally, make `message` and `name` consistent with `Error` object
(non-enumerable). Test that `console.log()` and `.toString()` calls on
internal `Error` objects with mutated properties have analogous results
with the standard ECMAScript `Error` objects.

PR-URL: https://github.com/nodejs/node/pull/15694
Fixes: https://github.com/nodejs/node/issues/15658
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>

1 files changed, 7 insertions, 9 deletions

diff --git a/lib/internal/errors.js b/lib/internal/errors.js
index 48ef2dcc3d..e3c18b48c7 100755
--- a/lib/internal/errors.js
+++ b/lib/internal/errors.js
@@ -22,15 +22,13 @@ function makeNodeError(Base) {
   return class NodeError extends Base {
     constructor(key, ...args) {
       super(message(key, args));
-      this[kCode] = key;
-    }
-
-    get name() {
-      return `${super.name} [${this[kCode]}]`;
-    }
-
-    get code() {
-      return this[kCode];
+      this[kCode] = this.code = key;
+      Object.defineProperty(this, 'name', {
+        configurable: true,
+        enumerable: false,
+        value: `${super.name} [${this[kCode]}]`,
+        writable: true
+      });
     }
   };
 }